I know this comment from ancient times of CGI.pm. I think it is for Netscape Navigator 4 or even an older version. It is present in the oldest version available on CPAN, v2.45 released 1998-Nov-25. At that time, Netscape Navigator 4.08 was the latest version, and many users still used NN 4.0 or NN 3.x.

NN has not seen a new release since 2008 and is effectively dead. I consider the commented hack legacy code, almost cargo cult. It does not hurt to have it there, but I doubt it has any effect with any browser released in the last years.

Alexander

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Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)